docs: def make_blocks(ec_infos, codewords):
      """\
      Returns the data and error blocks.
  
      :param ec_infos: Iterable of ECC information
      :param codewords: Iterable of (integer) code words.
      """
      data_blocks, error_blocks = [], []
      offset = 0
      for ec_info in ec_infos:
          for i in range(ec_info.num_blocks):
              block = codewords[offset:offset + ec_info.num_data]
              data_blocks.append(block)
              error_blocks.append(make_error_block(ec_info, block))
              offset += ec_info.num_data
      return data_blocks, error_blocks